Apparatus for scoring can lids



2 Sheets-Sheet 1 Filed Oct. 17, 1950 INVENTOR BEN/v 0 H444 Ems/0' ATTORNEYS Jan. 15, 1957 B. WALENSKY 2,777,410

APPARATUS FOR SCORING CAN .LIDS

Filed Oct. 17, 1950 2 Sheets-Sheet 2 INVENTOR 67 BENNO M ALENJ/f) BY 17 /kzf ATTOR NEYJ APPARATUS FOR SCORING CAN LIDS Benno Walensky, London, England Application October 17, 1950, Serial No. 190,559

Claims. (Cl. 113-15) The present invention concerns apparatus and method for scoring blanks preferably of metal which are intended to form readily removable walls or closures for containers and the like. The invention has found primary use in metal cans such as the tops or ends of tin cans containing food or other commercially vendable products where it may be desirable to remove the contents without special tools or even the well known can opener.

It is an object of the invention to provide apparatus for scoring a container top or wall in such a way that the residual thickness of the remaining wall portion at the root of the score is a constant within quite close tolerance throughout the length of the score. In this way the material at the base of the score has substantially the same strength throughout the length of the score and there is no weak point at which undesired rupture can start.

The invention has reference to apparatus for this purpose of the kind wherein the blanks to be scored are pressed between a scoring knife and a pressing or counterpressure unit.

In my British patent specification No. 556,334 apparatus of this general character is described wherein theblanks are pressed against the scoring knife by rollers or balls mounted in a rotatable carrier and subjected to pressure so that they roll under pressure on the blank.

Such a rotary unit or tool is not applicable to an ordinary or conventional type of press.

An object of the invention is to enable a rotary tool provided with rolling elements, to be used in an ordinary or conventional type of press, to press blanks'to be scored on to a scoring knife.

According to the present invention the rotary tool component is provided with a shank or stem which is rotatably mounted in a bearing sleeve adapted to fit in the reciprocatory ram or slide of a press of ordinary or conventional type, and means are provided on said rotary tool component for enabling rotational movement to be transmitted thereto from a prime mover.

The means for transmitting rotary motion to the rotary tool component may comprise a flexible shaft, a motor movable with the tool, or a train of gears. I p The prime mover may be mounted on the ram or slide, or it may be mounted on a fixed part of the press'and in the latter case transmit motion to the rotary tool component by means of a flexible shaft, or through a countershaft which rises and falls with the ram or slide of the press.

The rotary tool component may carry the rolling elements such as rollers or balls, or it may carry the scoring knife.

In order to enable every point of the score track in the blank to be rolled over at least once by the rolling elements, under full pressure, provision is made to cause a been brought together.

This dwell action may be achieved by operating the ram nited States Patent 0 2,777,410 Patented Jan. 15, 1957 ice or slide of the press through a suitably formed cam, or in the case of a crank-operated press, by providing for a predetermined vertical movement of the co-operating tool components in unison after they have been brought together, such unitary movement taking place against the action of cushioning means such as one or more springs or a buffer, or dashpot, or other hydraulic device, the cushioning means preferably being pre-loaded to enable the required maximum pressure to be exerted on the blank by the tool components directly they are brought together.

One example of the invention and its application to a crank operated press is illustrated by the accompanying drawing which is a part sectional elevation of the assembled apparatus, only those parts of the press being shown which are necessary for the understanding of the invention.

In the drawing:

Fig. l is an elevation partly in section of the upper part of one form the invention may take.

Fig. 2 is an enlarged detail elevation in section of the bottom part of one form of scoring tool cooperating with Fig. 1.

In the example illustrated the rotary tool component assembly 1, comprises a disc 2 carrying inner and outer rollers 3 and 4, respectively, mounted to rotate in an opening in the disc, on a pin 5, which is fixed in the disc; a press body 6 and a carrier cup 7 which is carried by the press body 6 and to which the roller carrying disc 2 is fixed by screws 8.

Only one set of rollers is shown, but more than one set is preferably provided. I

This rotary tool component assembly is carried by the ram 9 ofthe press.

For this purpose it is provided with a central stem or shank 10 of circular cross section which is rotatably mounted in a bearing sleeve 11, which fits in a vertical bore 12 in the ram 9 of the press.

The bearing sleeve has a flange or plate 13 at the bottom, which abuts against the bottom end of the ram and extends horizontally beyond the ram.

The upper end of the bearing sleeve 11 is recessed to receive the outer race of a ball bearing 14, the inner race being fitted on the upper end of the stem Ill.

The races of the ball bearing 14 are fixed by a locking ring 15 and clamping nut 16, which screws on to the end therein as described forms a unit which can be introduced as a whole into the bore of the ram 9, the rotary tool component thus being suspended from the upper ball hearing 14 and thrusting against the lower ball bearing 17, so that it is correctly centered and can rotate freely.

For the purpose of transmitting rotary motion to the rotary tool component 1, undisturbed by the up and ,down motion of the ram 9 of the press, a gear wheel 18 is keyed on the stem 10 beneath the thrust bearing 17, and meshes with a gear wheel 1% driven by a vertical countershaft 20, which passes through and is connected slidably by a feather key 21 with an upper gear wheel 22, so that while the shaft 23 can slide through said upper gear wheel 22, it is constrained to rotate therewith by key 21.

The counter-shaft 20 is divided and the adjacent ends thereof are connected by a universal ball-joint 23, or a sleeve.

The lower portion of the counter-shaft 20 is received in a bushing 24, in the extension of flange or plate 13, its lower end being keyed in the gear wheel 19' and se cured by a screw passing through an end cap 26.

Rotary motion is transmitted to the counter-shaft 20 by an electric motor 27, fixed on a base plate 28, which is bolted to a plate 29' on the frame of the press.

The motor 27 has a driving connection with the count er shaft 20, through intermeshing bevel pinions 30, 31, and a gear wheel 32, which meshes with the gear wheel 22.

The bevel pinion 31 and the gear wheel 32 are keyed on a vertical shaft 33 mounted at its upper end in a ball bearing 34 fitted in the top of an inverted U-shaped yoke 35 bolted to the base plate 28, the lower end of the shaft 33 being mounted in a ball bearing 36 fitted in the base plate 28.

The gear wheel 22 has a hub 37, which is received in a bearing bushing 38 fitted in the base plate 28 and is held in the bushing by a keeper plate 39.

As shown in Fig. 2 a scoring knife 40', which in the present example is circular, is mounted on a carrier 41, which is contained within a recess 41' in a main support 42' and beds on the bottom of said recess. The main support 42 beds on abase plate 43.

The carrier 41 has a diametricat slot 44 formed in the lower part thereof and is provided with a central bore 45 for receiving temporarily a centering rod (not shown) which is entered also in a bore 45' in the rotary tool component in performing the centering operation, the rod being removed on completion of the centering operation.

An ejector sleeve 56 is provided to eject the metal section such as a lid after it has been scored.

The ejector sleeve 46 is interposed between the wall of the recess 41 in the main support 42 and the carrier 41.

The ejector sleeve 46 has a diametrically arranged bar 47 at the bottom, which is accommodated in the slot 44 of the carrier 41.

The ejector sleeve 46 is operable by an ejector lever 48 which acts on a disc 49 connected by a rod 50 to the bar 47. Ejector lever 48 is operable through a bar 51 by a spring pusher arm 52.

In the example illustrated the ejecting action is performed manually, but it may be performed automatically by action of the press on a feeding mechanism.

The main support 42 for the knife 40 is screw-threaded externally to receive an adjustable stop sleeve 53 provided with a scale ring 54.

By screwing the adjustable stop sleeve 5311p or down to bring a selected scale marking on the ring into coincidence with a datum marking on a convenient fixture (not shown) the extent to which the upper rotary tool component presses the lid (inverted) on to the knife 40, in the scoring operation can be predetermined, so determining the thickness of the metal to be left beneath the score, since the outer rollers 4 on the upper rotary tool component will roll on the top of the stop sleeve 53 when the ram 9 of the press descends and said rollers 4 reach the stop sleeve 53, the inner rollers 3' thus being prevented from pressing the lid to be scored on to the knife beyond the predetermined extent.

In operation of the apparatus, so far described, when the motor 27 is started, it drives through the intermediate gearing 30, 31., 32 and 22, the counter-shaft 20, which transmits rotary motion to the rotary tool component 1 through the intermeshing gear wheels 19 and 18.

As the ram 9 of the press descends, the counter-shaft 20 slides downwards in unison, through the upper gear wheel 22, while still continuing to rotate by reason of its sliding keyed connection 21 with said upper gear wheel 22, so that rotation of the rotary tool component is not interfered with by the descending motion of the ram 9.

The lid to be scored is placed on the raised edge of the knife 40, within the adjustable stopsl'eeve 53, and as the ram 9 reaches the end of its stroke the lid is pressed onto the knife edge by the rotating tool? component 1 to form the score, the inner rollers 3 of the rotary tool component 1 rolling around the lid over the knife edge, under pressure of the ram, while the outer rollers 4 roll on the top of the adjustable stop ring 53 so ensuring an even score.

Where, as is desirable, the inner rollers 3 are to roll over every point of the score track more than once, in the application of the invention to a crank operated press the scoring knife 40 and its supports 41, 42 are mounted for axial movement against the action of a cushioning element or elements. Such a cushioning element is advantageously pre-loaded, so that as the ram 9 approaches the end of its downward stroke and the co-operating rotary tool component 1 and the scoring knife 40 are brought together with the lid to be scored between them the rotary tool component 1 and the scoring knife 40 move downwards in unison, against the action of the cushioning element while the rotary tool component 1 continues to rotate, thus, providing for the equivalent of a dwell at the end of the downward stroke of the ram 9, during which dwell the inner rollers 3 of the rotary tool component may be caused to roll under pressure over every point of the score track more than once. This dwell is continued at the beginning of the upstroke of the ram.

in. the present example, for the above purpose, the base plate 43 for the knife support assembly is arranged for vertical movement in a tool. housing 55 and is urged upwards against. a stop ring 56 by a stout spring 57, the housing 55 having a flange 58 by which it is supported on a. bolster 59 on the bed 60 of the press.

The stop ring 56 is screwed into the tool housing 55 so that its position can be adjusted vertically, a locking ring. 61 preferably being. provided to lock the stop ring 56 in its adjusted position.

The tool housing 55 has a depending cylindrical extension 62 to house the spring 57.

The lower end of the spring 57, bears on a disc 64 arranged Within the spring housing. 62, the disc having a threaded stem 65, which is screwed through the bottom of the spring housing 62 andis provided with. a turning head in the form of a nut 66 fixed on the stem by a pin 67, so that by turning the stem in the appropriate direction, the disc 64 can be raised to compress the spring 57 and so pre-load it to any required degree. A lock nut 68 is provided on the stem to bear against the bottom of the spring housing 62 to hold the stem 65 in its adjusted position.

When the rotary tool component 1 descends with the ram of the press and presses the lid to be scored on to the top edge of the knife 40, the rotary tool component 1 and the knife 40 with its. supporting assembly 41, 42 and the base plate 43 thereafter move downwards in unison, as a whole, against the action of the spring 57 until the downward stroke of the ram 9 is completed.

During this unitary downward movement, the inner rollers 3 of the rotary tool component 1 roll, under pressure, on the lid to be scored, over the knife edge, at least once and if desired more than once, to press the lid down on to the knife edge until the outer rollers reach and then runon the topof the stop sleeve 53.

On the return movement or upstroke of the ram 9, a corresponding unitary movement takes place during the initial portion of the stroke.

Under these conditions the inner rollers run around the lid over the track of the score; more than once, and uniform and satisfactory score is produced.

To prevent the vertically moveable part of the bottom tool from turning when the rotating part of the top tool presses on it the base plate 43' is provided with depending rods or bars, passing slidably through the bottom of the tool housing 55. Preferably two rods, 63, are provided in' spaced lateral diametrical position and a third one 69 in front of the base plate 43, this latter rod mainly servingas a measuring rod to indicate the degree of compression of the spring 57 and also the extent of lift of the base plate 43 in relation to the base of the recess in the tool housing 55.

For this purpose the rod 69 is provided with a suitably graduated scale 70 thereon, and two pointers are provided. One pointer 71 is attached to the disc 64 and passes through a longitudinal slot 72 in the wall of the spring housing 62, to indicate on the scale 70 the degree of compression of the spring 57.

The second pointer (not shown) is fixed to the tool housing 62 to indicate on the scale 70, or another scale (not shown) the extent of lift of the base plate 43 above the base of the recess in the tool housing 55. This scale would go from a zero point downwards, the zero point corresponding to the position of base plate 43, when resting on the bottom of the recess in the tool housing 55.

The measuring rod 69 also provides a check on the amount of give of the vertically movable part of the bottom tool, whilst the two co-operating tool parts are in touch with each other. For this purpose a clamp or clip may be attached to the rod 69, its lower end resting on the pointer attached to the spring housing 62. If rod 69 descends when the co-operating parts have closed together, the clamp, prevented by the pointer from descending with the rod 69, will be pushed upwards on the rod 69 and ascend in this position with the ascending rod 69. The distance of the base of the clamp from the fixed pointer then shows the amount of give.

The tool housing 55 with the spring 57 and associated parts therein, forms a self-contained unit which can be applied to a conventional crank operated press.

Where the invention is applied to a cam operated press the ram of the press is operated through a suitably formed cam, which provides for a dwell in the operation of the ram, at the end of its downward stroke, and during the initial part of the upward stroke.

It is to be understood that the invention is not confined to the particular embodiment described by way of example.

Thus, for instance, instead of mounting the motor on a fixed part of the press, it may be mounted on the ram of the press so that it moves with the ram, and in such case the motor may drive the rotary tool component through a flexible shaft and worm or bevel gearing, or through any suitable reduction gear.

Other transmission gearing can be adopted in place of that described, for instance, belt and pulley gearing, or chain gearing.

Balls, instead of rollers can be used as the rolling elements in the rotary tool component.

I claim:

1. In combination in a scoring press apparatus for scoring metal closures for containers to provide a residual thickness of metal at the base of the score which varies not more than a few thousandths of an inch, a knife element of closed configuration mounted on said press,

stop means of closed configuration mounted on said press and surrounding said knife element, a rotatably mounted roller assembly housing having a plurality of roller elements journaled therein, means to move said rollers into cooperating scoring relation with said knife element, said roller elements being constructed of such length as to ride on said stop means and to press a closure against said knife element to produce a required score and drive means for rotating said roller assembly comprising a stationary motor and means to transmit the rotary motion of the motor to the rotatable roller assembly in any position of the latter.

2. The combination set forth in claim 1, and a resilient mounting for said knife element.

3. The combination set forth in claim 1, and means carried by said press to provide a dwell in the kinematic cycle whereby said rollers press against said knife element a sufficient time so that said knife is traversed by said rollers as a group at least once.

4. The combination set forth in claim 1, said means to transmit rotary motion comprising a splined shaft and a gear driven by said motor slidably mounted with respect to said shaft, a gear for driving said roller assembly and universal means connecting said splined shaft to said last named gear.

5. In combination in a scoring press apparatus for scoring metal closures for containers to provide a residual thickness of metal at the base of the score which varies not more than a few thonsandths of an inch, a knife element of closed configuration mounted on said press, stop means of closed configuration mounted on said press in spaced concentric relation to said knife element, a rotatably mounted roller assembly housing having a plurality of roller elements journaled therein, means to move said rollers into cooperating scoring relation with said knife element, said roller elements being constructed of such length as to ride on said stop means and to press a closure against said knife element to produce a required score and drive means for rotating said roller assembly comprising a stationary motor and means to transmit the rotary motion of the motor to the rotatable rotor assembly in any position of the latter.

References Cited in the file of this patent UNITED STATES PATENTS 

